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A. M. JOHNSON.

SECRET 000e LATCH AND LocK.

N FILED MA 2 9| APPLlcAT R. AY 2o. |919. 1,3 1 6,448. Patented Sept. 16, 1919.

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NNNNNN OR BY @WW/f A. M. JOHNSON.

SECRET DOOR LATCH AND LOCK. APPLICATION FILED MAR. 2. |911. RENEwED MAY 20. |919.

vUNITED sTATEs PATENT orricn .AMASA M. JOHNSON, 0F NEW YORK, N. Y.

SECRET-DOOR LATCH AND LOCK.

Specification of Letters Patent. Patented Sept 16, 1919,v

Appnation mea March 2, 1917, 'serial No. 152,080. Renewed May 2o, 1919. serial No. 298,554. y

To all whom t may concern:

Be it known thatI, AMAsA M. JOHNSON, a citizen of the United States, residing at New York, in the county of New York and `State of New York, have invented new and useful Improvements in Secret-Door Latches and Locks, of which the following is a specification.

rl`his invention relates to locks and latches, and more especially to those devices in which both these features are combined; and the object of the same is to produce such an article capable 0f application to a secret door which is preferably one of a num-ber of panels separating a room or apartment from a hallway or the like. The present invention is an improvement on my Patent No. 1183464 issued May 16th, 1916, wherein the same general principle with respect to the latch was employed, butJ in the present case I add the feature of a so-called dead latch capable of being operated with a key and including a bolt which when projected prevents thegactuation of they latch proper of this invention until said bolt is again retracted.

The invention involves details hereinafter more fully described and claimed, and shown in the drawings wherein:

Figure 1 is an elevation of three panels whereof the intermediate one constitutes a door which it is proposed to fasten with my improved device, the same being shown in this view as closed; and

Fig. 2 is a similar view with the door open.

Fig. 3 is an elevation with the front plate of the lock casing removed, showing the parts in one position; and Fig. 4 is a face view of the inner plate of the lock casing looking fromthe left of Fig. 3. .These views show the parts in what 1 will call the first position. y

Fig. 5' is ya similar view of the mechanism of the lock with the parts in the second position, including the keeper partly inl section; and Fig. 6 is a view similar t0 Fig. 5 with the parts -in the third position. Figs. 7 and 8 arev sections on theline 7-7 and S-S respectively ofFig. 5, and Figs. 9 and 10 are sections on the line 9-9 and 10-10 Vrespectively of Fig. 6; while Figs. 11 and 12 are sectional details showing the third and fourth positions of parts as referred to hereinafter.

Figs. 13 and 14 are respectively a face view Y and a rear edge view of the keeper;

Figs. 15 and 16 are horizontal sections on the lines 15-15 of Fig. 6 and 16-16 of Fig. 3 respectively, showing the dead latch in different'positions.

Fig. 17 is a detail of the key.

The door structure shown herein comprises panels P, between' two of which Vis inter# posed a door panel D swinging between the floor F and the topv rail beneaththe tran-v som T, and `closing against a stop strip S which is seen exposed in Fig.V 2. The'door is opened toward the rear. Above the transom the wall N continues tothe line of the ceiling C, or maybe paneled if desired.

Strips of molding M may surround the pan-- els, and will be `attached tothe fixed rails of those panels which do not move,l` whereas it should be mounted on and carried by the movable panel which constitutes theV door D. As seen in Fig. 1,*the structure is such that a person not Afamiliarnwithl it would hardly discover the existence of a door. On the forward side I may employfaknob K with which to open the door. I

Coming now to the detailsof construction, the casing 1 of the lock, which is by preference set into the frame rather than the edge of the door,l contains Ythe, sliding bolt 2 having a peculiar form of head and the stop bolt 3 whose inner end stands normally flush with the face plate 4 of the casing as seen in Figs. 3 and 4,.and springs 5 control kthe action ofthese bolts as set forth below, but need not be'described in detail as lany suitable'form of springs which will perform the function will answer. y'The lock casing also preferably containsa dead latch to be described later, and a' chamber in the lock casing may contain the plunger best seen in Fig. 9 and alsov to-bedeslcribed later, or this plunger may be mounted in an independent casing within thestop strip S. The head of the bolt 2 is shown in Fig. 5 as of T-shape so that it rises above and depends below the shank of the bolt, and this I prefer although it is not absolutely necessary. Either or both of the upright extensions will `necessarily stand oblique so as to constitute a cam 6 of about the shape best seen in section in Figs.v 7 and 9, this cam being shown in end View in Fig. 4 at 6 las crossing the line of the shank 2 of the bolt itself, and the face plate 4 as having loo an opening 7 of suilicient size to permit the entire head 6 toI be pressed into the face plate as in the fourth position described below.

yThe keeper, best seen in Figs. 13 and 14 and in coactive position with the lock in Fig. 5, is right-angular in cross section as best seen in Fig. 15 and has a face plate 14 and a rear edge plate 15. The face plate is cut with a T-shaped opening 17, which, with its shank 12, admits the head and shank of the main bolt 2; and the shank 12 of the opening passes through the angle between the two plates and constitutes a shank for a second T-shaped opening 18v in the rear edge plate 15 as seen in Fig. 14. The overhanging portions of the plate are beveled as at 16 adjacent the opening 17, and again at 19 adjacent the opening 18 for coaction with the head or cam 6 in a manner yet to be described, and within the angle of the metal between the shanks of these two openings is formed a rest 11 best seen in Fig. 11 where it is idle or in Fig. 9 where it is active. Across the face of the rear edge 15 is cut a notch 13 which appears in end view in Fig. 13 and in elevation in Fig. 14, which notch vis for the tip of the stop bolt 3 as will be described below. The keeper is secured flush in the edge of the door D as seen in Fig. 2.

The operation of so much of my invention as has been described is as follows: Vhen the door D shown open in Fig. 2 is closed, the projecting portions or lugs above and below the shank 12 of the openings in the keeper plate and at the angle of the latter pass astride the shank of the main bolt 2 as indicated in Fig. 5 and the bevels 19 ride behind the cam 6 so that the head and shank of the main bolt 2 are drawn outward to the first position shown in Fig. 7, at which time the springs 5 will cause the stop bolt 3 to be projected as seen in Fig. 8A so that its tip stands within the notch 13. .l ust at the time that the bottom of the notch strikes the tip of the stop bolt 3 to check the further movement of the door, the inner edge of the cam 6 rides off the bevel '19 (as it is about to do in Fig. 7 and drops onto the rest 11 to assume the set position shown in Fig. 9. This releases the spring pressure which gave a forward impulse to the stop bolt 3, and the latter is automatically retracted to the position shown in Fig. 10. The door now stands locked because the angle within the keeper is engaged with the inner edge of the cam, and the keeper can not be moved downward in Fig. 9 until such engagement is interrupted. To unlock and open the door it is necessary to move the parts to the third position as shown in Fig. 11, which is done by pushing the door a little further closed. The result is that the rest 11 moves out from under the inner edge of the cam 6, and the spring on the main bolt 2 retracts it with the cam to the position here shown; then when the door is started open the bevel 16 strikes the outer face of the cam. and pushes the latter with the main bolt 2 into the lock casing as seen in Fig. 12, so that the keeper can move past it as indicated by the arrow therein.

Thus it will be seen that, in eifect, the door is latched closed by pushing it gently to closed position, and it is unlatched and opened by pushing it further closed and then under the action of the spring the door is forced open.

In Fig. 9 is best seen a device which I preferably employ for preventing the door from passing the first position of Fig. 7 when it is closed ordinarily, and for preventing it from being driven past this position by pressure of air within the compartment, which pressure might be generated by slamming some other door. This device consists of a plunger 20 mounted within a casing 21 which, as suggested above, might be a part of the lock casing 1, but which in any event is inset into the stop trip S which is shown uninterrupted in Fig. 7 but which is interrupted for this purpose in Fig. 9, and the last named view is to this extent a modification or amplification. The plunger is borne normally inward by a spring 22 and its projected tip 23 will strike the edge plate 15 of the keeper at about the point 24 indicated in Fig. 14. With the use of this ampliiication, when the door is closed to the first position, its keeper strikes the tip of the plunger and further closing movement is checked unless the door is pushed pur posely; but when the door is pressed inward to the second position, the spring 22 of the plunger yields and the parts become locked as seen in Fig. 9. To unlock the door as described above, it is only necessary to press it yet farther inward with suflicient force to overcome the spring of the plunger as will be clear.

So much of my invention as has already been described may be said to be a latch, and the lock features of my invention are as follows :-Referring now to Figs. 4, 15 and 16, the numeral 30 designates the bolt of a dead latch, which bolt has a slightly curved body and is slidably mounted through an opening 31 in the face plate 4 of the lock casing and pressed forward by a. spring 32. Its inner end is pivoted at 33 to a block 34 slidably mounted within said casing` and having a pin 35 which projects through a transverse' slot 36 in said face plate and travels in a notch 37 in the keeper so that it is not struck by the latter when the door is opened and closed by hand. llVhen the parts are set by movement of this pin man* ually to the locking position shown in Fig. 15, the projected tip of the bolt 30 stands in position to be struck by the edge 15 of the'keeper at a time when the door reaches its locked position shown in Fig. 9, and therefore it will be impossible to press the door yet farther inward so that the cam 6 may slip o` the rest 11 asseen in Fig. 11, until the dead latch is first retracted to the position as shown in Fig. 16. es the operator can not gain access to the pin 35, I have provided a key 40 as shown 1n Fig. 17, the same having a narrow thin blade 41 provided in one edge near its tip with a notch or if desired, a plurality of notches 42, and this key may be inserted between the edge of the door and the face plate of the lock casing as indicated in Fig. 5, and passed over the pin. Now a slight inward movement of the key will obviously retract the dead latch and move it to the position shown in Fig. 16. The normal spacing between the edge or' the door and the Jface plate 14 of its keeper on one hand, and the edge of the door frame and the face plate 4 of the lock casing on the other hand, will be sufficient for the passage of the thin blade 41 of the key 40; but if desired, a little slot or opening 43 may be cut through the stop strip S as indicated in dotted lines in Fig. 15, so that the key could be inserted from the other side and yet the existence of this opening` would hardly be noticed. As the dead latch is usually applied by a person on'the inside of a room, however, the opening 43 may not always be necessary, and when extreme secrecy is sought this opening will be omitted.

Thus it will be seen that I have employed the essential principles of the invention set forth in my former patent, to the extent only that the main bolt or latch bolt has a cam-shaped head whose two Jfaces are oblique to the length of its shank, and the keeper has a substantially right-angular body with the outer ends of its arms beveled as at 19 and 16 for the passage of the edges of the cam across them, and an angular rest for engaging the inner edge of the cam when the parts stand in locked position. In addition thereto, however, the present case discloses the feature of a dead latch which may be thrown into active position manually but must be retracted by means of a key, and which when used has the effect of locking the device which would otherwise be a latch. The present case also makes provision for a plunger mechanism which is employed for .the purpose of forcing the door open. As

stated above, this involves the addition of a knob to the outside oit' a door, and on occasions this might not be desirable. I would not, therefore, be limited to the employment of this amplification, nor do I wish to be limited to the specc details of construction further than as covered by the appended claims.

By slightly pulling on the knob K, the

carried by one element and having a rest within its angle, and a spring-retracted latch bolt carried by the other element and having an oblique cam on its head adapted for coaction with said member and to stand on its rest when the device is locked; of a dead latch, means for projecting it into` the path of the moving member at a point to prevent the rest from being disengaged from said cam, and means for retracting said latch.

2. In a lock of the character described, the combination with a right-angular member carried by one element and having a rest within its angle, and a spring-retracted latch bolt carried by the other element and having a cam on its head adapted for coaction with said member and to stand on its rest when the device is locked; of a dead latch movably mounted in the Xed member, means for projecting it by hand when the members are separated so that its tip will stand in the path of the moving member at a point to prevent the rest from being disengaged from said cam, and a key for retracting the latch at a time when the members are locked.

3. In a secret door lock, the combination with a right-angular keeper carried by the door and having a rest within its angle, the lock casing carried by the frame, and a spring-retracted bolt within the casing having an oblique cam on its head adapted for coaction with the said keeper and to stand on its rest when the parts are locked; of a block slidably mounted within said casing, a dead-latch-bolt pivoted at its inner end to said block, the face-plate of the casing having an opening for the bolt and a transverse slot adjacent thereto and the bolt being curved so as to be projected through said opening when the block is moved, and a pin on the block projecting through said slot.

4. In a secret door lock, the combination with a right-angular keeper carried by the door and having a rest within its angle, the lock casing carried by the frame, and a spring-retracted bolt within the casing having a cam on its head adapted for coaction with the said keeper and to stand on its rest when the parts are locked; of a lblock slid-V ably mounted within said casing, a deadlatch bolt pivoted at its inner end to said block, the face-plate of the casing having an opening Jfor the bolt and a transverse slot adjacent thereto and the bolt being projected through said opening when the block is moved, and the keeper having a notch registering with said opening, a pin on the block projecting through said slot and over which said notch moves as the door closes, and a key for engagement With said pin7 for the purpose set forth.

5. In a secret door look, the combination with a right-angular keeper carried by the door and having a rest Within its angle, the lock casing Carried by the frame, and a spring-retracted bolt within the casing haw lng a cam on its head adapted for ooacton with said keeper and to stand on its rest when the parts are looked; of a dead-latch bolt movably mounted Within the easing, means for projecting it into the path of the keeper at a point to prevent the rest from being disengaged from said4 cam, means 4for retraoting this bolt at will, and a springproj eoted plunger carried by the door easing and with which the keeper contacts When the parts stand looked.

In testimony whereof, I aHiX my signature. 20

AMASA M. JOHNSON.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, I). C. 

